Created attachment 368286 [details, diff] patch, works for me nmap-6.40-r1.ebuild is migrated to python-r1 eclasses, but hard masked, also it has several mistakes: missing REQUIRED_USE for python USE flags NMAP_PYTHON_DEPEND is pointless and should not have '|| (' pygtk dep does not have slot and [${PYTHON_USEDEP}] ebuild does not run 'python_optimize "${ED}"/$(python_get_sitedir)' P.S. Was it really required to rename gtk USE flag?
Created attachment 389122 [details, diff] patch, works for me Fixed building with python disabled and PYTHON_TARGETS="".
+*nmap-6.25-r1 (11 Nov 2014) + + 11 Nov 2014; Mike Gilbert <floppym@gentoo.org> +nmap-6.25-r1.ebuild, + nmap-6.47.ebuild: + Call python_optimize in src_install, and backport python changes to + nmap-6.25-r1. Bug 498726 by Nikoli.